Hello Kurt,
Thank you very much for taking care about my question.
I will write my answers below your questions.
On Sat, Oct 19, 2019 at 10:56 PM, Kurt Poulsen wrote:
1. Did you use a male SMA to N female adaptor directly fitted to the SMA
No.
female adaptor for Ch0 ?
Just a male-female thread saver, as could be seen on the photo.
2. Did you before using the NanoVNAuser ensure the NanoVNA was correctly
calibrated directely at the NanoVNA Ch0 female adaptor with the supplied
calibration kit ?
The nanoVNA was calibrated at the *Reference Plane* shown in the photo.
The used *Calibration Kit* was the supplied one.
The *Open* SMA part was replaced with a *female-female adapter*.
2a. and did a sweep of a 25 to 50cm SMA test cable show better result?
I can not understand the question.
3. The test cable is probably too long and shall be a N type cable with no adaptors fitted
I do not have that.
4. Your NanoVNA has a poor bridge as NanoVNA as far as I know has no internal error correction
I measured the 50 Ohm resistance with a 3 VDC supply and a 4 digit *Ampere meter* and *Volt meter*
The nanoVNA CH0 port shows 49.23 Ohm.
The 50 Ohm load shows 50.72 Ohm.
A self made 50 Ohm load from 2 SMD 0805 100 Ohm 1% resistors in parallel shows 49.99 Ohm (interesting).
There is probably more reasons and it would be better if you explained in details you setup
Please see the attached photo: nanoVNA_50cm-RG402-open2_f-f_DSC08152.jpg
I have attached 2 screen captures from nanoVNA-saver with the S11 measured 50 cm RG402 coax cable.
nanVNA-Saver_50cm-RG402-open2.png - End of RG402 SMA male plug open
nanoVNA-saver_50cm-RG402-open2_f-f.png - End of RG402 male plug with *female-female adapter*
It is interesting how much the *Parallel X* capacity changed.
The nanoVNA-saver has an additional calibration with 5 segments.
What can I enter in the window Calibration->Calibration standards in order to improve the measurement?
73, Rudi DL5FA
